Pulley



(No Model.) I 2 Sheets-Sheet 2.

` l J. W, OSBORNE.

PULLEY, ROLLER, 0R PRICTIN WHEEL.

Vantented Nov. 27, 188,3;

- @f4 A N UNITED STATES )PATENT JOHN w. o's'o'nrn, or WASHINGTON, DISTRICT or coLnMBIaASSIG-Non To WILLIAM n. FORBES, or BOSTON, MASSAcIInsnTrS.V

P'ULLEY, ROLLER, on FmoTl'oNfwHEEL.

SPECIICATION Vtorturing part of Letters `Patent N o. 29,3467, dated November. 2'?,A 1 883. y,

' .ippnmnfm njea embers, 1ere (Xn man all whom. it'iaay concern..-

Bc it known that I, JOHN XV. 'Osonln Vof lWashington, District' of Columbia, have in-" vented a new and useful Improvementn the' Construction of Pulleys, Rollers, -and Friction- VVheels, of which the-following 'isa specification. 'f

This invention is related, gcner'ally,to the devices employed for' receiving and communicatiV ing motion by means of belts and bearinglsur- ,faces generally, and specifically to the class 'of contrivanees known -as expansible .pulleys 'and wheels."` As now constructed, for the `most-part, the 'diameter of'such pulleys, rol1- and at the same time praeticallycireular. ln'

my inventionI sustain (conceutrically with the axis of the 'pulley or wheel) a circular hollow shell of elastic Inat'erialdivided wholly o'r in part by 'radial saw-cuts or in other' manner, placing the Same between flanges or disks which can be mutually approached. By this `arrangem,ent lateral pressure can bc applied tothe Sides ofthe divided shell, subject to which the same is forced to change its formin such a ina-nner as to alter the diameter of the part of the pulley over which abelt travels, or

which hasfrictional contact with sonic other bearing-surface.

In ythe dra-wings which form -part of this specication, Figure 1 shows apulley or rollerin cross-section, -inwhichthe elastic cxpansible materlal is metal or hard rubber.y

Fig. 2 is a side-elevation of thc same. vrcpr'escntsthc same pulley i-n front elevation nig. 3

after expansion'. Fig. 4 is a side elevation of the sanie.- Flg. 5 is a cross-section of the Inetalliclsh'ell alone which is used in the forego ing. Fig'. 6 is a sideelev'ationof the same before division nto sectors. Fig. 7 is a cross .Section cfa pulley in which met al and v ulcanci ples involved in I'ny invention.

ized rubher'are combined to furnish the ela'sf tic'expansibleinaterial. Fig. Sisafrntele-z ration ofthe foregoing. l Fig.'9 is the cross-fv section of a metallic 'expansible 'pulley ofmodied construction. Fig 1'0 is a section of thesameon line l l of Fig. 9. 11 is the cross-section of an expansible pulley, showing,

a further mdiaeation. Fig. 12 shows in 'Iona gitudinal section a portion of the expansible', material usedlin the foregoing'. Fig. 13 shows, in crosssection, apulley having a large range of expansibility. Fig. 14 is a side elevation f ofthe same withthe' compressing-nut removed. Fig. 15 showsin pla-n one sector of the expansibleportion before bending. Fig. 1.6 is a. cross-section of a pulley in which liard rnbberisthe elastic material used.v Fig. 17V

isv a section of the same on line 2'21 Figs. l to 6, inclusive, illustrate the construe tion of an expansible pulley. based on the printic metallic shell, a, `is used, which, acted upon bylatcral pressure, undergoes 'radial expan- '-sio n. 'An annular shell ofthe description `usedis shown, independently of the rest ofthe pulley, in Figs. 5 andli. It may be spun from brass, and its hardness and elasticity will be improved if it is afterward rolled with rolls adapted for the purpose. AS shown in Fig. 5, the sides of the shell are conical for a short distance lfrom their inner edges'at b b, and Ithese are connected by an elliptical or similar curve, which is to form the faceot' the pulley. The Stock or body of the pulley has attached to it the flange c, and upon its cylindrical part slides the sleeve d, which carries a sifnilar flange, c. The sides ofboth anges are undercutin such a way as to be parallel to the conical part b of the annular shell (l, which is grasped by them, and the circular opcningsin thc latterare accurately fitted lto the cylindrisuch a shell of metal is caught, as shown, be-

In it 'an elas- `cal shoulder left for them at f f, Fig. 1. YVhen. j

tween the side flanges of thepullcy,`nopress ure exerted by the nut g will effect its expansion, because such4 a change would involve a stretching and elongation l of its perimeter, which, under the circumstances, is impossible.

`I' accomplish the end inffview, however, by

making a large number of fine 'saw-ctsvradi# Ico a "j for belting, 4the belt should occupy` only the ally through the sh'ell and parallel lo its axis,

v dividing lits exposed-curved surface only, in .a manner made -intelligible by. the drawings,

I so .thatthe working' portion ot' the pulleyface shall'lconsistof a number of a-rched'springs extending,` from side to lside, all united throughout the conical part l) b 'on both sides, where no. expansion or eXtension -takes p'lace. In

this arrangement, when pressure isapplied by screwing up the nut `r/ the veonvexity ot' the face' is increased, as seen' in Fig. 3, and a d'il .-lation'of each saw-cuttakes place, which is greatest/in the middle of the i'aee,'as seen in tant that the conical part grasped by theV Figui. To insure uniformityof the curve as-l snmed by the exposed .portion on both sides .ofthe middlelin'e upon 'the face, it is importlanges should remainimmovable, as if held: 'byythesame.v This is aecomplishedvbygiving tothe-'sides of the shell so gra-sped the divergin'g conical form described, and iitting` the `circular openings in' the same accurately upon the eylindricalfshouldersf lt willbe readily undei'rstoodthat by thisarrangementit is inlpossiblior the sides ot' the shell, at their in- -ner edges, to lem-je the iianges without meet i'nggwith'.resistance 'and wedging. tlnhnselves tighter,- and the resultis that, the sides being solidlyheld,` the movement otfthe elastic part .is definite and the same at both sides..

Y This form ofexpansible pulley is well adapted tov act as anadjustable roller in contact with reciprocating or rotating sui-laces, and 'as aguidefi'oller, its :uljnstability giving; it great advantages for these pnrposes.- 'When usd' i central part.ot'the face.

For certain purposes the shell' for .this p ullcyn'nay be' made ot' hard rubber, which will befond. tojwork :xceedingly well, being pos- -ses's'ed of-greatand permanent elasticity. In'v "1' that case, however, .l Iconstruct "the rubber I jointly.

s'hell yerymueh thicker' (relairelyto-the size of the pulley) than appears in' the drawings, which are intended to represent' brass.

"In'Figs 7 and Sa pulley is shown in which.- vnleaniyed rubber' and metal are used con- .lhe'nmin 'features ot'lthis modification arc'preeiselylike the infeceding, the saine general. ligurebeing used; but the metallic `tlfshell, after division,with'the saw. isencircled .lfhisistightly applied v'and holds its place with-.great tenacity, entering the.sa\\'-euts :to `a slight extent. Its effect is to give strength to the dividedshell by establishing.;` continuity of structure between.the-separated.curved sln'ingxsbut it also performs the useful function ol' adding to their elasticity-'that is, their power of recov.

eri-ngaheii.- original'i'orm when the pressure whielrhas increased their eonvexity isV re.4 moved. This rubber-ringv l1J may also'bemade to give toia pulley ofthisconstruetiona much ,-.iiatter face when expanded tlianit wouldhave without that addition. g This is done by con- ,.f'strnctingrthe rubberring so that itsfundefr cease? surface corresponds in shape to thatof theuni expanded shell, while its upper surface re-A mains iiat, or even in some cases concave.

In the drawings the ring h/is shown fiat, and

the effects of expansion on it are seen in Fig. 1l; vbut it obviously may be made"V-.shaped, so as to' carry around belt, should that be de. sirable. i.' i

AA. pulley constructed with the compound elastic ring, as here described, is wel'l adapted to ac t as arollerin a variety of cases,

'as well as forcarrying metallicandother belting, and it is especially adapted forxvorking as afrietion-wheelin variable positions against a smooth-face wheel for the transmission of 'great changes in speed. The rubber takes an excellent grip' on such surfaces and ywears slowly.

justability, but with a metallic face which 'is flat, or-neaily so,at all times, I adopta fur therinodification of this principle. Such pulleyisshown in Figs. 9 and 10 .bot11 being sectional views. Theform here givento the shell is such that the face, being flat,resists the-latmadeof steel, and it may-be used with-anyexpansible pulley ba'scd' upon the. principle. herein set forth, to supplement' the elasticity of the elastic 'material interposed between the Hang-es.

Vheu a metallic c xpansible pulley isurequired-vcalculatedj to withstand hard usage without injuryfI forni the elastic material be-l tweelrthe fianges of a spiral spring'made'ot wire. A ,portion of such' a' spiral is shown in;

Thisis a very stift'.l

longitudinal seetionin Fig-.12. 'l'nFigJlit'isshown in e'rossfsection and 'position at m,y

lapped round thelsle'eve n. i This spiral may or may-not be compressed,atter winding,' to the 'flattened elliptical shape seen in Fig. 11. By so doing the lateral force requisite forits cxpansion (applied by the nut e) must be I,f greater; but the face remains flatter. Each turn of theV spiral may'also be 'illed awaytapering toward its point of contact wkith thesleeve, as shown in .1 `ig. 112, so th'atw-.hen'grasped bytheilanges.k

all the-convolutions ot' the spiral will be in contact before expansion;s or the tapering' may extend only as far as the 'edges ot' the llanges, the object being to hold the wire steadily with` out Iapossibility of shift. For a pulley so construetedlsteel 'wire maybe used; but brass can. be drawn so hard and stift' that in most cases it will 'prove suicient. libe distinctive adcease?. E@

vantage which this kind of pulle5T possessesis inthe great strength and perfect elasticity of the Wire,`as compared with any otherrl'brm which can be given to the metal employed.

In figs. 13 and 1i an expansible pulley is' represented which admits of greatalteraticn in the diameter of its werking-zone. The elas-I tic "part in this case is best constructed ci'v spring-steel plates, punched out or otherwise eut from ilat sheet-steel, all of the same size and forni, which is easily determined. Fig. 15 shows in plan one such blader TheL-ilanges 1) and q oi' the pulley have each of them a ring,

5r and s, en their inner faces, 'which can be drawn up by t-hebelis t t. The extremities a ol' the blades 'fic i, de, (the ilauges p and@ haviugbeen setat their nearestliniit.) are then crowded in between the rings r and s and the iiangesp and q, respectively, the forni of the' extremities being such as t0 accurately lill the" available space, aller which the belts "t- 1., d'0.,

are screwed up tight; lVhen the compression nut e is new unsere-Wed, the elasticity 0f thel blades le u', Xe., will i'eree themevable flange back, and the pulleir will take its smallest di-v ameter, as shown in Fig. ln this position the edges oi the blade` all lie close together, but theyn'illseparate more or lessiu the convex part, as Jthe d imneter is increased by screw in :fnp the. nut fr. The thick rubber ring, as described and. shown in lligs. ri and S, may be used withaud iliade part el" this pulley, as fol' all others: in which a divided elastic shell Y i'orins the expansible peripheryv under the -u'orliiugiace.V i

Figs. i6 and 17 `illustrate a pulleyv en the same. principle asihose already described," but differing' from Them in constructiomso that the application oi lateral pressure causes a de` crease in its diameter, and the removal or less- A .AS. shown, this i'iulley is designed to carry a round ening of that jiressure an expansion.

belt,and i'er 'it hard rubber may be ccnveniently used. "The shell .fr is divided by'radial saw-euts throughout i'he whole depth el.' the curved pari, lherround edge only remainingl lferent ferm.

solid. This is caught in suitable recesses by .the flanges g/ 31, both ofi which slide upon the body of the pulley7 moved bythe boli-s s s.

The increase cf pressure increases ,the ecuvVerity cf the dividedV shell and lessens its di`v aineter. By using a vulcanized rubber ring; with this forni 0f shell its,bearing-slimline can be fitted fo'r`a` flat belt, which change can be also. made by giving the shell 'originally a diflhe shell can' of.' course be made ci other1` material as well as hard. rubber. y

Having thus described my invention, what l' p claim, and desire'to secure byLettei-s Patent, is

1. An expunsible pulley haring its circumference composed cfa series ei'spri n es ci' metal 0r equivalent rigid elastic material, said- 4. In an expansible'pulley, an elastic shell forming the circumference el' the pulley and divided in the direction 0i" the axis, in com bination with a spiral spring', applied subst-an tiallgv as described, te supplement. the elasticitj,v of said shell.

5. 'In au expausible pulley7 an elastic eircuniferentiul shell divided in the direct-ien oi' tire axis, and having conical sides b b, cour bined with compressing side llanges corre-` spondingl y undercut, and p rovided with shells ff, fitted te the openings in the shell, as de! scribed and shown.

JOHN XV. OSBORNE. lVituesses:

Gino. F. Giannini, Il. C. YOUNG.

seI 

